Checking the valve guides (BMW 3 Series E30)

When carrying out repair work on cylinder heads with leaky valves, it is not enough to grind or replace the valves and valve seats. In addition, it is imperative to check the wear of the valve guide bushings. This is especially important on engines that have high mileage. Worn guide bushings do not ensure valve centering, which causes high oil consumption. If wear is significant, the riveted guide bushings should be replaced (work must be performed at a service station).

Remove the valve.

Clean the guide bushing with a cylindrical brush.



Insert the valve into the guide sleeve from the combustion chamber side and check its play when moving the valve laterally in both directions.

To check, apply a steel ruler. The clearance should not exceed 0.8 mm; on 316i models produced since September 1988 and 318i models produced since September 1987 - 0.5 mm.

If necessary, replace the riveted guide bushings (work must be performed at a service station).